There is however a cluster encounter candidate, ASCC 13, crossing the path of X Per 24.4\(\pm \) 9 Myr ago, compatible with the maximum age of 29.5 Myr attainable by the 15.5 M\(_{\odot }\)  secondary [1]}. The cluster is measured to be 33\(\pm \) 15 Myr old. Using the age-mass relation in Eq. REF , the primary would have been roughly 27.6 M\(_{\odot }\)  at birth. The maximum ZAMS mass of the secondary is 14.7 M\(_{\odot }\)  meaning it should have gained at least about 1 M\(_{\odot }\)  of material from the primary during initial mass transfer, bringing it to its current mass of 15.5 M\(_{\odot }\) .
